The present embodiments relate to the acquisition and processing of measurement data by a combined magnetic resonance and X-ray device.
Magnetic resonance imaging is a powerful tool to acquire image data (e.g., in medical imaging). Due to physical and technical constraints, a three dimensional image acquisition in magnetic resonance imaging takes a certain amount of time. The imaging is therefore susceptible to a reduction in image quality and image artefacts due to a movement of a test subject during the image acquisition. This is problematic when living test subjects (e.g., patients) are imaged.
One approach to reduce imaging artefacts due to motion is using an optical tracking of markers that are attached to a test subject. The position of the imaged slice may be adjusted as a function of movement data that is generated by tracking these optical markers. This approach may not be used to track an internal movement of the test subject. This is also a rather laborious approach, since the markers are to be attached to the test subject and there is additional hardware and software used to track these markers.
It is also possible to approximate a movement solely from the acquired magnetic resonance data. For example, an iterative minimization of the entropy of the resulting real space image may be applied. This approach may be useful to compensate for minor movements. Larger movements may hardly be compensated by this approach, since there is no information about the real movement available, and optimization algorithms may get stuck at a local optimum that does not necessarily compensate the real movement.